I started by figuring out how much strike water I need to mash a 10gal batch of oatmeal stout. 9gal I looked at my 36qt mash tun and quickly figured out that 9gal of water and almost 30lbs of grain would not fit. As I started mashing my hose in my cooler started leaking. By the time I got it dumped into another cooler. Mash run fixed and back into mash mode I was down under 140.